Golang : How to generate Code 39 barcode?
Additional tutorial on how to use https://github.com/boombuler/barcode package to generate code 39 barcode. Code adapted from previous codabar tutorial.
Here you go :
package main
import (
"fmt"
"github.com/boombuler/barcode"
"github.com/boombuler/barcode/code39"
"github.com/disintegration/imaging"
"github.com/llgcode/draw2d"
"image"
"image/color"
"image/draw"
"os"
)
func main() {
code := "SOCKETLOOP PORT 443"
fmt.Println("Generating code39 barcode for : ", code)
// see https://godoc.org/github.com/boombuler/barcode/code39
bcode, err := code39.Encode(code, false, false)
if err != nil {
fmt.Printf("String %s cannot be encoded\n", code)
os.Exit(1)
}
// scale to 300x20
bcode, err = barcode.Scale(bcode, 300, 20)
if err != nil {
fmt.Println("Code39 scaling error : ", err)
os.Exit(1)
}
// now we want to append the code at the bottom
// of the Codabar
// Create an new image with text data
// From https://github.com/llgcode/draw2d.samples/tree/master/helloworld
// Set the global folder for searching fonts
draw2d.SetFontFolder(".")
// Initialize the graphic context on an RGBA image
img := image.NewRGBA(image.Rect(0, 0, 250, 50))
// set background to white
white := color.RGBA{255, 255, 255, 255}
draw.Draw(img, img.Bounds(), &image.Uniform{white}, image.ZP, draw.Src)
gc := draw2d.NewGraphicContext(img)
gc.FillStroke()
// Set the font Montereymbi.ttf
gc.SetFontData(draw2d.FontData{"Monterey", draw2d.FontFamilyMono, draw2d.FontStyleBold | draw2d.FontStyleItalic})
// Set the fill text color to black
gc.SetFillColor(image.Black)
gc.SetFontSize(14)
gc.FillStringAt(code, 50, 20)
// create a new blank image with white background
newImg := imaging.New(400, 200, color.NRGBA{255, 255, 255, 255})
//paste the codabar to new blank image
newImg = imaging.Paste(newImg, bcode, image.Pt(20, 50))
//paste the text to the new blank image
newImg = imaging.Paste(newImg, img, image.Pt(50, 90))
err = draw2d.SaveToPngFile("./code39.png", newImg)
if err != nil {
fmt.Println(err)
os.Exit(1)
}
// everything ok
fmt.Println("Code39 barcode generated and saved to code39.png")
}
Sample output :
References :
See also : Golang : Generate Codabar
By Adam Ng
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